In order to meet performance, efficiency, emission and other possible requirements over a wide range of operating conditions and environments, an automotive system may have more input variables than output variables. The input variables to a plant, controlled using actuators, are used to control the output variables of the plant process. For example, a conventional gasoline engine will have at a minimum, throttle, spark advance and fuel inputs in order to control the speed and/or the air/fuel ratio of the engine. In more advanced engines, variable valve timing (VVT) and continuously variable transmissions (CVTs) represent additional control inputs that may be applied to a plant.
The excess of inputs, and thus excess of actuators, is desirable in attempting to improve performance, efficiency, and the lice. And although these features of a control system may not be reflected through variables that are controlled to a specific set point the features are important with respect to obtaining the best operation of an engine or plant.
Over-actuated systems can be found in vehicle power train systems, vehicle stability control systems, modern aircraft and robotic systems. However, a cost effective and practical control system, method of design and/or strategy that optimizes an overall force, moment or generalized effect using actuators of the system is lacking. Therefore, a control system for over-actuated systems in which the individual features of the various actuators are incorporated to provide optimized inputs to a plant is desirable.